Abstract A high brightness field sequential color telvision display system utilizing electronically controllable color switching of a tri-color liquid crystal filter positioned in front of a monochrome cathode ray tube. The liquid crystal structure provides a color change in response to electronic pulses and color switching is the result of an orientation aligned in the direction of the light path or in a direction substantially normal to the light path. The orientation of the host crystal domain results in a similar orientation of associated dye domains or molecules. For each of the basic red, green and blue colors, a field sequential operation is performed by applying switching pulses so that a field is provided normal to the direction of the light path in a liquid crystal cell of the selected color. To rapidly clear a selected cell to a clear state, a field is applied substantially parallel to the light path. The color image is formed in the field sequential fashion by placing the spectral filter in front of a cathode ray tube and observing the various intensities of white light on the face of the tube through the composite filter.
A field sequential television display system comprising: a cathode ray tube having a display screen scanned in sequential fields, liquid crystal filter means positioned adjacent to said screen to provide a light path and including three liquid crystal cells each having dye domains to provide different color characteristics, said cells each responding to an electric field so that one cell orients the dye domains substantially normal to the light path and the other two cells orient the dye domains substantially parallel to the light path, each cell having a flat structure containing the liquid crystal and dye material and first and second interdigital conductors on one side of the structure and a plane conductor on the other side of the structure, and a control source coupled to said first and second digital filter means for sequentially varying the selected color as a function of said sequence of fields by applying positive and negative potentials to said first and second digital conductors of a first cell; a reference potential to said plane conductor and positive potentials to both said first and second interdigital conductors of the other cells to develop the electric fields.
Claim 2
Dependent Claim
192 words
A field sequential television display system comprising: a cathode ray tube having a display screen scanned in sequential fields, liquid crystal filter means positioned adjacent to said screen to provide a light path and including three liquid crystal cells each having dye domains to provide different color characteristics, said cells each responding to an electric field so that one cell orients the dye domains substantially normal to the light path and the other two cells orient the dye domains substantially parallel to the light path, each cell having a flat structure containing the liquid crystal and dye material and first and second interdigital conductors on one side of the structure and a plane conductor on the other side of the structure, and a control source coupled to said first and second digital filter means for sequentially varying the selected color as a function of said sequence of fields by applying positive and negative potentials to said first and second digital conductors of a first cell; a reference potential to said plane conductor and positive potentials to both said first and second interdigital conductors of the other cells to develop the electric fields.
Claim 3
Dependent Claim
20 words
The system of claim 1 in which a polarizer is provided between said screen and said liquid crystal filter means.
Claim 4
Dependent Claim
15 words
The system of claim 2 in which said sequence of fields has an interlace format.